Postfix relay question

[kule]

Hi Guys,

Wonder if anyone can shed any light on this. I have 2 servers one which uses a postfix relay to the main postfix email server.

This all works great (thanks for the tutorials Falko) however I have noticed on the email server when emails are sent via the relay:

example.com = x.x.x.1 = relay
mail.example.com = x.x.x.2 = postfix email server

postfix/smtpd[xxx]: warning: x.x.x.1 address not listed for hostname mail.example.com

As I understand it; it's because the reverse dns of x.x.x.1 doesn't equate to mail.example.com however as it's connecting from the relay shouldn't be trying a lookup of x.x.x.1 to example.com not mail.example.com?

It's not a biggie as it's all working but I would like to understand whats happening and fix it if possible.

Thanks
Luke

[falko]

Does mail.example.com point to x.x.x.1?

[kule]

No:

example.com = x.x.x.1 = relay
mail.example.com = x.x.x.2 = postfix email server

example.com[x.x.x.1] is my webserver which relays emails to the postfix on mail.example.com[x.x.x.2]

[falko]

Can you post your main.cf from both servers?

[kule]

example.com[relay]:

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no

append_dot_mydomain = no

myhostname = example1
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = localhost.localdomain, localhost
relayhost = mail.example.com
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options =
mynetworks = 127.0.0.0/8
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all

readme_directory = /usr/share/doc/postfix
html_directory = /usr/share/doc/postfix/html

mail.example.com[mail server]

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no

append_dot_mydomain = no

# TLS parameters
smtpd_tls_cert_file=/etc/postfix/smtpd.cert
smtpd_tls_key_file=/etc/postfix/smtpd.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${queue_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${queue_directory}/smtp_scache

myhostname = mail.example.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = mail.example.com, localhost.localdomain, localhost
relayhost =
mynetworks = 127.0.0.0/8
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all

#Virtual Setup
virtual_alias_domains =
virtual_alias_maps = proxy:mysql:/etc/postfix/mysql-virtual_forwardings.cf, mysql:/etc/postfix/mysql-virtual_email2email.cf
virtual_mailbox_domains = proxy:mysql:/etc/postfix/mysql-virtual_domains.cf
virtual_mailbox_maps = proxy:mysql:/etc/postfix/mysql-virtual_mailboxes.cf
virtual_mailbox_base = /home/vmail
virtual_uid_maps = static:5000
virtual_gid_maps = static:5000

smtpd_sasl_auth_enable = yes
broken_sasl_auth_clients = yes
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
transport_maps = proxy:mysql:/etc/postfix/mysql-virtual_transports.cf
virtual_create_maildirsize = yes
virtual_mailbox_extended = yes
virtual_mailbox_limit_maps = proxy:mysql:/etc/postfix/mysql-virtual_mailbox_limit_maps.cf
virtual_mailbox_limit_override = yes
virtual_maildir_limit_message = "The user you are trying to reach is over quota."
virtual_overquota_bounce = yes
proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $virtual_mailbox_maps $virtual_mailbox_domains $relay_recipient_maps $relay_domains $canonical_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks $virtual_mailbox_limit_maps

header_checks = regexp:/etc/postfix/header_checks

content_filter = amavis:[127.0.0.1]:10024
receive_override_options = no_address_mappings

readme_directory = /usr/share/doc/postfix
html_directory = /usr/share/doc/postfix/html

[sjau]

have you tried using the IP of the main server or adding an entry to the /etc/hosts file? Can you ping mail.domain.com from the relay server?

[kule]

Hi sjau

Yep you can ping mail.example.com from the relay server.

Just to clarify again - everything works ok and email sent from the relay is delivered. I just get a weird warning on the mail server, which I would like to understand & if possible fix.

Can you clarify about putting an entry in the /etc/hosts file? Did you mean on the mail server?

Kind Regards
Luke

[falko]

Can you change
myhostname = example1
to myhostname = example.com
on the example.com server?

What's in /etc/mailname on both servers?

[kule]

I changed the /etc/hostname & the myhostname to example.com - fingers crossed I think that sorted it.

/etc/mailname was example.com in both so I adjusted the mail server to be mail.example.com as well anyways.

Many thanks for your time with this.

Luke